1. Field of the Invention
The present invention relates to a fixing device arranged in an electrostatic electrophotographic image-forming machine such as a copier, a laser printer, a facsimile or the like. More particularly, the invention relates to a fixing device comprising a thermally fixing roller, pressing rotary means pressed onto the thermally fixing roller and a separation member for separating the paper from the outer peripheral surface of the thermally fixing roller.
2. Description of the Related Art
A fixing device mounted on an image-forming machine representatively comprises a thermally fixing roller, pressing rotary means such as a pressing roller that is brought into pressed contact with the thermally fixing roller, and a separation member for separating the paper from the outer peripheral surface of the thermally fixing roller. A toner image is fixed while a paper bearing the toner image transferred onto one surface thereof passes through a nipping portion between the thermally fixing roller and the pressing roller. The paper to which the toner image is fixed is discharged onto a paper discharge tray by a discharge roller.
The separation member is disposed to prevent jamming that may occur in case the papers wrap around the thermally fixing roller. The separation member representatively comprises separation pawls (see, for example, JP-A-10-333465). The separation pawls are brought into contact with the surface of the thermally fixing roller to effectively separate the paper that is going to wrap around the thermally fixing roller away from the thermally fixing roller. While the fixing is being conducted, however, the separation pawls are brought into contact with the surface of the thermally fixing roller giving rise to the occurrence of such inconveniences as an increased wear on the outer peripheral surface of the thermally fixing roller (usually, surface of an elastic layer made of a silicone rubber or the like) and scratches causing a decrease in the life of the fixing device and making it necessary to renew the fixing device at the time of regular maintenance of the image-forming machine.